This invention relates to electric water heaters and, more particularly, to removable heating elements for electric water heaters.
Electric water heaters typically include one or more heating elements, each of which is threaded into a boss on the side of the water tank. The heating rod portion of the element usually extends generally straight and diametrically through the tank. Consequently, the length of the heating rod is limited by the inside diameter of the water tank.
Most conventional heating rods have a maximum wattage rating per square inch of surface area and operation at higher wattages significantly reduces life. Also, operational life of a heating rod having a given surface area can be increased by decreasing the wattage. Accordingly, in order to increase the operational life of the heating element, it is desirable to make the heating rod as long as possible with the constraints that the heating rod must fit through the tank boss for initial installation and replacement and the heating rod must not strike obstructions in the tank, such as the cold water dip tube, the anti-corrosion anode and the hot water outlet pipe, while being rotated as the heating element is being threaded into or unthreaded from the tank boss.